1. Field of the Invention
The present invention relates to, a dryer apparatus for drying a web.
More specifically, the present invention relates to, a dryer apparatus for drying tissue.
2. Background Information
In the papermaking industry, a paper making machine ejects paper pulp onto a moving drainage screen so that water is permitted to drain from the formed web. In the case of a tissue machine, the formed web is removed from the drainage screen by a pick-up roll so that the web can be guided and supported by a felt. The felt guides the web of tissue onto the heated outer surface a rotating Yankee dryer. In recent years it has been discovered that large amounts of water can be pressed from the web by an extended nip press or shoe press which cooperates with the heated surface of the Yankee dryer.
However, because the felt supporting the web has been in contact with the web from the forming section, there is a tendency for such felt to have absorbed a considerable quantity of water from the web prior to passage of the web supported by the felt extending through the extended nip. Accordingly, because the extended nip removes a relatively large amount of water from the web, the water absorbing capacity of the felt is not in an optimum water absorbing condition when such felt enters the extended nip.
The present invention completely overcomes the aforementioned problem of the water absorbing capacity of the felt by the provision of a separate press felt which only extends through the extended nip and is therefore in an optimum condition for absorbing the relatively large quantities of water removed from the web during passage thereof through the extended nip.
Therefore, it is a primary feature of the present invention to provide a dryer apparatus for removing water from a web of tissue that overcomes the problems associated with the prior art arrangements.
Another feature of the present invention is the provision of a dryer apparatus that enables the removal of relatively large quantities of water from a web of tissue as the web moves through an extended nip cooperating with a heated surface of a Yankee dryer
A further feature of the present invention is the provision of a dryer apparatus that enables a press felt to extend through an extended nip with an optimum water absorbing capacity.
Other features and advantages of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description of a preferred embodiment of the present invention contained herein.